The present invention relates generally to the art of bearings for facilitating shaft rotation. More particularly, the invention relates to a bearing assembly which incorporates an improved sealing arrangement while also having an improved securement and removal feature.
Bearing assemblies are often designed to be quickly attached to a shaft. Typically, the bearing assembly is first slipped along the shaft to the desired position. Once there, the inner ring of the bearing assembly is secured utilizing one of various clamping techniques.
A common clamping technique involves the use of a tapered adapter having a tapered outer surface. Such a tapered adapter defines an axial bore for receipt of a shaft therethrough and further defines a radial slot extending along its length. A bearing assembly having a receiving bore with a tapered inner surface is situated about the tapered adapter. The bearing assembly and the tapered adapter are forced axially into one another. As a result, the tapered adapter is closed around the shaft. Further movement of the bearing assembly along the tapered outer surface achieves a press fit between the various components.
The result of high pressure between components, low angle of taper between the opposed tapered surfaces and the coefficient of friction of metal-to-metal militates that a high force is necessary to remove the bearing assembly from the tapered adapter. In addition, fretting corrosion often develops at the interface of the bearing bore and the adapter. This corrosion further increases the force required to remove the bearing. The lack of a convenient technique for applying force from the shaft to the bearing face has frequently necessitated that the bearing itself be destroyed with a cutting torch in order to effect its removal. In addition to destruction of the bearing, this technique risks damage to the shaft itself. Because the shafts are not of a single diameter and are of varying lengths, the use of standard removal tools such as gear pullers and the like has not been considered practical.
Various configurations of seals are often utilized to isolate the interior of the bearing assembly from the ambient environment. For example, it may be desirable to prevent lubricant within the bearing from escaping too quickly to the ambient environment, thus presenting an unsightly appearance on or around the bearing. Additionally, it is desirable to prevent contaminants in the ambient environment from penetrating the bearing interior and causing damage to the bearing elements located therein.
The degree of sealing necessary for a particular application will depend upon the duty requirements of such application. For example, a light seal may be suitable for high speed and normal contaminate service. In other applications, it may be necessary to provide a bearing assembly having enhanced sealing characteristics. For economic and other considerations, it is desirable that a single bearing assembly be provided that may be easily adapted from a light sealing to a heavy sealing configuration.